#1
What are the advantages of Koa wood in a guitar body? What kind of tonal properties does it offer? How does it differ from other types of woods?
#2
Historically, koa tops have appeared primarily on small bodied Hawaiian guitars and ukueles, although recent koa dreadnoughts and custom guitars have been popular.

Koa produces a predominately bright treble response with less volume than spruce, but the slight loss in volume is overshadowed by the extreme beauty of the grain.

When used in the back and sides of a guitar, Koa seems to have a bass response that is slightly less than that of rosewood and treble response that is slightly less than that of mahogany. The result is a very equally balanced instrument. Typically, koa tops are available on special order and custom instruments.